package com.nCoV.EpidemicSurveillance.config;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;
import org.springframework.stereotype.Service;

/** 
* @author 作者 罗穆健: 
* @version 创建时间：2020年1月4日 下午11:02:45 
* 类说明 
*/
@Service
public class MyFilterSecurityInterceptor extends AbstractSecurityInterceptor implements Filter {
	
	 	@Autowired
	    private FilterInvocationSecurityMetadataSource securityMetadataSource;

	    @Autowired
	    public void setMyAccessDecisionManager(MyAccessDecisionManager myAccessDecisionManager) {
	        super.setAccessDecisionManager(myAccessDecisionManager);
	    }


	    @Override
	    public void init(FilterConfig filterConfig) throws ServletException {

	    }

	    @Override
	    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

	        FilterInvocation fi = new FilterInvocation(request, response, chain);
	        invoke(fi);
	    }


	    public void invoke(FilterInvocation fi) throws IOException, ServletException {
	        //fi里面有一个被拦截的url
	        //里面调用MyInvocationSecurityMetadataSource的getAttributes(Object object)这个方法获取fi对应的所有权限
	        //再调用MyAccessDecisionManager的decide方法来校验用户的权限是否足够
	        InterceptorStatusToken token = super.beforeInvocation(fi);
	        try {
	            //执行下一个拦截器
	            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
	        } finally {
	            super.afterInvocation(token, null);
	        }
	    }

	    @Override
	    public void destroy() {

	    }

	    @Override
	    public Class<?> getSecureObjectClass() {
	        return FilterInvocation.class;
	    }

	    @Override
	    public SecurityMetadataSource obtainSecurityMetadataSource() {
	        return this.securityMetadataSource;
	    }

}
 